RT8010/RT8010A pdf datasheet (

The RT8010/A is a high-efficiency Pulse-Width-Modulated
(PWM) step-down DC-DC converter. Capable of delivering
1A output current over a wide input voltage range from
2.5V to 5.5V, the RT8010/A is ideally suited for portable
electronic devices that are powered from 1-cell Li-ion
battery or from other power sources such as cellular
phones, PDAs and hand-held devices.
Two operating modes are available including : PWM/Low-
Dropout autoswitch and shut-down modes. The Internal
synchronous rectifier with low RDS(ON) dramatically reduces
conduction loss at PWM mode. No external Schottky
diode is required in practical application.
The RT8010/A enters Low-Dropout mode when normal
PWM cannot provide regulated output voltage by
continuously turning on the upper PMOS. RT8010/A enter
shut-down mode and consumes less than 0.1μA when
EN pin is pulled low.
The switching ripple is easily smoothed-out by small
package filtering elements due to a fixed operating
frequency of 1.5MHz. This along with small WDFN-6L 2x2
and WQFN-16L 3x3 package provides small PCB area
application. Other features include soft start, lower internal
reference voltage with 2% accuracy, over temperature
protection, and over current protection.